<PAGE>

                                                                    EXHIBIT 10.1

                         SECURITIES PURCHASE AGREEMENT

      This Securities Purchase Agreement (this "AGREEMENT") is made and entered
into as of March 30, 2006 (the "EXECUTION DATE"), by and among Northwest
Biotherapeutics, Inc., a Delaware corporation (the "COMPANY"), and each of the
purchasers listed on Schedule A attached hereto (collectively, the "PURCHASERS"
and individually, a "PURCHASER").

                                    RECITALS

     WHEREAS, the Company desires to sell to the Purchasers, and the Purchasers
desire to purchase from the Company, up to an aggregate of 39,467,891 units
(each a "UNIT"), each Unit consisting of one (1) share of common stock, par
value $.001 per share, of the Company ("COMMON STOCK") and a five year warrant
(a "WARRANT") to purchase one half (1/2) of one share of Common Stock, on the
terms and conditions set forth in this Agreement; and

      WHEREAS, the Company and each Purchaser are executing and delivering this
Agreement in reliance upon exemption from securities registration afforded by
Regulation D ("REGULATION D") as promulgated by the Securities and Exchange
Commission (the "SEC") under the Securities Act of 1933, as amended (the
"SECURITIES ACT").

      NOW, THEREFORE, in consideration of the foregoing, the mutual promises
hereinafter set forth, and other good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged, the parties hereto agree as
follows:

      1. AGREEMENT TO PURCHASE AND SELL STOCK.

     (a) Company Authorization. The Company's Board of Directors has authorized
the issuance and sale, pursuant to the terms and conditions of this Agreement,
of up to 39,467,891 shares of Common Stock (the "PURCHASED SHARES") and up to
19,733,945 Warrants, substantially in the form attached hereto as Exhibit A.
Each one (1) Warrant included in the Units shall be exercisable to purchase one
(1) share of Common Stock at $0.14 per share (the "PURCHASED WARRANTS" and
together with the Purchased Shares, the "PURCHASED SECURITIES"). Subject to
their terms and conditions, the Purchased Warrants shall be exercisable at any
time and from time to time from and after the date hereof through and including
March 30, 2011.

     (b) Agreement to Purchase and Sell Securities. Subject to the terms and
conditions of this Agreement, each Purchaser, severally and not jointly, agrees
to purchase, and the Company agrees to sell to each Purchaser, at the Closing
(as defined below), that number of Units set forth opposite such Purchaser's
name on Schedule A attached hereto. The purchase price of each Unit shall be
$0.14 (the "PER UNIT PRICE") and shall be payable as hereafter set forth.

     (c) Use of Proceeds. The Company intends to apply the net
proceeds for working capital and general corporate purposes as determined by the
Company from time to time.

     (d) Obligations Several, Not Joint. The obligations of each
Purchaser under this Agreement are several and not joint with the obligations of
any other Purchaser, and no

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Purchaser shall be responsible in any way for the performance of the obligations
of any other Purchaser under this Agreement. The decision of each of the
Purchasers to purchase the Purchased Securities pursuant to this Agreement has
been made by such Purchaser independently of any other Purchaser. Nothing
contained herein, and no action taken by any Purchaser pursuant hereto, shall be
deemed to constitute the Purchasers as a partnership, an association, a joint
venture or any other kind of entity, or create a presumption that the Purchasers
are in any way acting in concert or as a group with respect to such obligations
or the transactions contemplated by this Agreement. Each Purchaser shall be
entitled to independently protect and enforce such Purchaser's rights,
including, without limitation, the rights arising out of this Agreement, and it
shall not be necessary for any other Purchaser to be joined as an additional
party in any proceeding for such purpose.

      2. CLOSING. The purchase and sale of the Purchased Securities shall take
place at the offices of the Company, at 11:00 a.m. eastern time, not later than
two (2) Business Days (as defined below) following the Execution Date, or at
such other time and place as the Company and Purchasers representing a majority
of the Purchased Securities to be purchased, mutually agree upon (which time and
place are referred to in this Agreement as the "CLOSING"). At the Closing,
against delivery of full payment for the Purchased Securities sold hereunder by
wire transfer of immediately available funds in accordance with the Company's
instructions and the Company shall issue and deliver to each Purchaser (i) one
or more stock certificates registered in the name of each Purchaser (or in such
nominee name(s) as designated by such Purchaser in the Stock Certificate and
Warrant Questionnaire, attached hereto as Appendix I, (the "STOCK CERTIFICATE
QUESTIONNAIRE")), representing the number of Purchased Shares set forth opposite
the appropriate Purchaser's name on Schedule A hereto, and bearing the legend
set forth in Section 4(j)(i) herein and (ii) the number of Purchased Warrants
set forth opposite the appropriate Purchaser's name on Schedule A hereto, and
bearing the legend set forth in Section 4(j)(ii) ; provided, however, the
Company may furnish to each Purchaser a facsimile copy of the warrant
representing the Purchased Warrant and of the stock certificate(s) representing
the Purchased Shares purchased by such Purchaser no later than the second
Business Day following the Closing Date, with the original warrant and original
stock certificate(s) to be delivered to such Purchaser by overnight courier no
later than the third (3rd) Business Day following the Closing Date. Closing
documents, other than the warrants representing the Purchased Warrants and the
stock certificates representing the Purchased Shares, may be delivered by
facsimile on the Closing Date, with original signature pages sent by overnight
courier.

      For purposes of this Agreement, "CLOSING DATE" means the date of the
Closing, and "BUSINESS DAY" means any day except Saturday, Sunday and any day
which shall be a federal legal holiday or a day on which banking institutions in
the State of New York are authorized or required by law or other governmental
action to close.

      3. REPRESENTATIONS, WARRANTIES AND CERTAIN AGREEMENTS OF THE COMPANY. The
Company hereby represents and warrants to each Purchaser that, except as set
forth in the SEC Documents (as defined below) or in the Disclosure Letter
attached hereto as Exhibit B (the "DISCLOSURE LETTER"):

            (a) Organization Good Standing and Qualification. The Company is a
corporation duly organized, validly existing and in good standing under the laws
of the State of

                                      -2-
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Delaware and has all corporate power and authority required to (i) own, operate
and occupy its properties and to carry on its business as presently conducted
and (ii) enter into this Agreement and the other agreements, instruments and
documents contemplated hereby, and to consummate the transactions contemplated
hereby and thereby. The Company is qualified to do business and is in good
standing in each jurisdiction in which the failure to so qualify would have a
Material Adverse Effect. As used in this Agreement, "MATERIAL ADVERSE EFFECT"
means a material adverse effect on, or a material adverse change in, or a group
of such effects on or changes in, the business, operations, financial condition,
results of operations, assets or liabilities of the Company.

            (b) Capitalization. The capitalization of the Company is as follows:

                  (i) The authorized capital stock of the Company consists of
300,000,000 shares of Common Stock and 100,000,000 shares of preferred stock,
par value $.001 per share ("PREFERRED STOCK").

                  (ii) As of March 29, 2006, the issued and outstanding capital
stock of the Company consisted of 19,078,048 shares of Common Stock and
32,500,000 shares of Preferred Stock. The shares of issued and outstanding
capital stock of the Company have been duly authorized and validly issued, are
fully paid and nonassessable and have not been issued in violation of any
preemptive or other similar rights.

                  (iii) As of March 29, 2006, the Company had (a) 337,146 shares
of Common Stock available for future grant under the 1998 Stock Option Plan; (b)
420,956 shares of Common Stock available for future grant under the 1999
Executive Stock Option Plan; (c) 2,423,320 options available for grant under the
2001 Stock Option Plan; and (d) 147,500 options available for grant under the
2001 Nonemployee Director Stock Incentive Plan.

                  (iv) As of March 29, 2006, (a) an aggregate of 216,045,989
shares of the Company's capital stock were issuable in respect of, or pursuant
to exercise, exchange or conversion of outstanding promissory notes (including
the conversion of all accrued interest thereon as of March 29, 2006) held by
Toucan Capital Fund II, L.P. and Toucan Partners, LLC (the "Toucan Entities");
(b) an aggregate of 145,000,000 shares of the Company's capital stock were
issuable in respect of warrants, options and similar purchase rights held by the
Toucan Entities; (c) an aggregate of 2,664,266 shares of the Company's capital
stock are issuable in respect of, or pursuant to exercise, exchange or
conversion of outstanding promissory notes (including the conversion of all
accrued interest thereon as of March 29, 2006) held by current and former
employees, officers and directors of the Company; (d) an aggregate of 4,465,330
shares of the Company's capital stock were issuable in respect of warrants,
options and similar purchase rights held by current and former employees,
officers and directors of the Company; and (e) an aggregate of 1,368,525 shares
of the Company's capital stock were issuable pursuant to the exercise of
warrants held by other parties.

      With the exception of the foregoing in this Section 3(b), there are no
outstanding subscriptions, options, warrants, convertible or exchangeable
securities or other rights granted to or by the Company to purchase shares of
Common Stock or other securities of the Company and

                                      -3-
<PAGE>

there are no commitments, plans or arrangements to issue any shares of Common
Stock or any security convertible into or exchangeable for Common Stock.

            (c) Subsidiary. The Company does not have any subsidiaries, and the
Company does not own any capital stock of, assets comprising the business of,
obligations of, or any other interest (including any equity or partnership
interest) in, any person or entity.

            (d) Due Authorization. All corporate actions on the part of the
Company necessary for the authorization, execution, delivery of, and the
performance of all obligations of the Company under this Agreement, including
the authorization, issuance, reservation for issuance and delivery of all the
Purchased Securities being sold under this Agreement and the Common Stock
issuable upon exercise of the Purchased Warrants (the "WARRANT SHARES"), have
been taken and no further consent or authorization of the Company, the Company's
board of directors (the "BOARD OF DIRECTORS") or the Company's stockholders is
required, and this Agreement constitutes the legal, valid and binding obligation
of the Company, enforceable against the Company in accordance with its terms,
except (i) as may be limited by (1) applicable bankruptcy, insolvency,
reorganization or other laws of general application relating to or affecting the
enforcement of creditors' rights generally and (2) the effect of rules of law
governing the availability of equitable remedies and (ii) as rights to indemnity
or contribution may be limited under federal or state securities laws or by
principles of public policy thereunder.

            (e) Valid Issuance of the Purchased Securities.

                  (i) Purchased Shares. The Purchased Shares will be, upon
payment for the Units by the Purchasers in accordance with this Agreement, duly
authorized, validly issued, fully paid and non-assessable, free and clear from
all taxes, liens, claims and encumbrances with respect to the issuance of such
Purchased Shares and will not be subject to any pre-emptive rights or similar
rights.

                  (ii) Purchased Warrants. The Purchased Warrants to be issued
pursuant to this Agreement will be, upon payment for the Units by the Purchasers
in accordance with this Agreement, duly authorized and validly issued, free and
clear from all taxes, liens, claims and encumbrances with respect to the
issuance of such Purchased Warrants and will not be subject to any pre-emptive
rights or similar rights.

                  (iii) Warrant Shares. The issuance of the Warrant Shares
issued or issuable from time to time upon the exercise of the Purchased Warrants
will be, and at all times prior to such exercise, will have been, duly
authorized, duly reserved for issuance upon such exercise and payment of the
exercise price of the Purchased Warrants, and will be, upon such exercise and
payment, validly issued, fully paid and non-assessable, free and clear from all
taxes, liens, claims and encumbrances with respect to the issuance of such
Warrant Shares and will not be subject to any pre-emptive rights or similar
rights.

            (f) Compliance with Securities Laws. Subject to the accuracy of the
representations made by the Purchasers in Section 4 hereof, the Purchased
Securities will be issued and sold to the Purchasers in compliance with
applicable exemptions from (1) the

                                      -4-
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registration and prospectus delivery requirements of the Securities Act and (2)
the registration and qualification requirements of all applicable securities
laws of the states of the United States.

            (g) Governmental Consents. No consent, approval, order or
authorization of, or registration, qualification, designation, declaration or
filing with, or notice to, any federal, state or local governmental authority or
self regulatory agency on the part of the Company is required in connection with
the issuance and sale of the Purchased Securities to the Purchasers by the
Company or the consummation of the other transactions contemplated by this
Agreement, except (i) such filings as have been made prior to the date hereof,
(ii) the filings under applicable securities laws required to comply with the
Company's registration obligations under Section 5(a) of this Agreement and
(iii) such additional post-Closing filings as may be required to comply with
applicable state and federal securities laws, including, but not limited to, the
filing of a Form D relating to the sale of the Purchased Securities pursuant to
Regulation D.

            (h) Non-Contravention. Assuming the accuracy of the representations
and warranties made by the Purchasers in Section 4 hereof, the execution,
delivery and performance of this Agreement by the Company, and the consummation
by the Company of the transactions contemplated hereby (including the issuance
of the Purchased Securities and the Warrant Shares), do not: (i) contravene or
conflict with the certificate of incorporation, as amended (the "CERTIFICATE OF
INCORPORATION") or bylaws, as amended (the "BYLAWS") of the Company; (ii)
constitute a violation of any provision of any federal, state, local or foreign
law, rule, regulation, order or decree applicable to the Company; or (iii)
constitute a default or require any consent under, give rise to any right of
termination, cancellation or acceleration of, or to a loss of any material
benefit to which the Company is entitled under, or result in the creation or
imposition of any lien, claim or encumbrance on any asset of the Company under,
any material contract to which the Company is a party or any material permit,
license or similar right relating to the Company or by which the Company may be
bound or affected, except in the case of clauses (ii) and (iii), for such
violations, breaches or defaults as would not reasonably likely to have a
Material Adverse Effect.

            (i) Litigation. There is no action, suit, proceeding, claim,
arbitration or investigation ("ACTION") pending or, to the Company's knowledge,
threatened: (i) against the Company or its activities, properties or assets, or
any officer, director or employee of the Company in connection with such
officer's, director's or employee's relationship with, or actions taken on
behalf of, the Company that is reasonably likely to have a Material Adverse
Effect, or (ii) that seeks to prevent, enjoin, alter, challenge or delay the
transactions contemplated by this Agreement. The Company is not a party to nor
subject to the provisions of, any order, writ, injunction, judgment or decree of
any court or government agency or instrumentality that is reasonably expected to
prevent, enjoin, alter, challenge or delay the consummation of the transactions
contemplated by this Agreement or is reasonably likely to have a Material
Adverse Effect. No Action is currently pending nor does the Company currently
intend to initiate any Action that is reasonably likely to have a Material
Adverse Effect. The SEC has not issued any stop order or other order suspending
the effectiveness of any registration statement filed by the Company under the
Securities Act or the Securities Exchange Act of 1934, as amended (the "EXCHANGE
ACT").

                                      -5-
<PAGE>

            (j) Compliance with Law and Charter Documents. The Company is not in
violation or default of any provisions of the Certificate of Incorporation or
the Bylaws. The Company has complied and is currently in compliance with all
applicable statutes, laws, rules, regulations and orders of the United States of
America and all states thereof, foreign countries and other governmental bodies
and agencies having jurisdiction over the Company's business or properties,
except for any instance of non-compliance that has not had, and would not
reasonably be expected to have, a Material Adverse Effect. The Company is not in
default (and there exists no condition which, with or without the passage of
time or giving of notice or both, would constitute a default) in any material
respect in the performance of any bond, debenture, note or any other evidence of
indebtedness in any indenture, mortgage, deed of trust or any other material
agreement or instrument to which the Company is a party or by which the Company
is bound or by which the properties of the Company are bound, which default
would be reasonably likely to have a Material Adverse Effect or which would be
reasonably likely to have a Material Adverse Effect on the transactions
contemplated by this Agreement.

            (k) Material Non-Public Information. The Company has not provided,
and will not provide, to the Purchasers any material non-public information
other than information related to the transactions contemplated by this
Agreement, all of which information shall be disclosed by the Company pursuant
to Section 9(m) hereof.

            (l) SEC Documents.

                        (1) Reports. The Company has filed in a timely manner
all reports, schedules, forms, statements and other documents required to be
filed by it during the last twelve months with the Securities and Exchange
Commission (the "SEC") pursuant to the reporting requirements of the Exchange
Act and the rules and regulations promulgated thereunder. The Company's Annual
Report on Form 10-K for the fiscal year ended December 31, 2004, as amended (the
"FORM 10-K"), its quarterly reports on Form 10-Q for the fiscal quarters ended
March 31, 2005, June 30, 2005, and September 30, 2005 (the "FORM 10-Qs"), and
any Current Report on Form 8-K for events occurring since December 31, 2004
("FORM 8-Ks") filed by the Company with the SEC (the Form 10-K, the Form 10-Qs
and the Form 8-Ks are collectively referred to herein as the "SEC DOCUMENTS")
have been made publicly available via the SEC's EDGAR database. Each of the SEC
Documents, as of the respective dates thereof (or, if amended or superseded by a
filing or submission, as the case may be, prior to the Closing Date, then on the
date of such filing or submission, as the case may be), (1) did not contain any
untrue statement of a material fact nor omit to state a material fact necessary
in order to make the statements made therein, in light of the circumstances
under which they were made, not misleading and (2) complied in all material
respects with the requirements of the Exchange Act and the rules and regulations
of the SEC promulgated thereunder applicable to such SEC Document.

                        (2) Sarbanes-Oxley. The Chief Executive Officer and the
principal accounting and financial officer of the Company have signed, and the
Company has furnished to the SEC, all certifications required by Sections 302
and 906 of the Sarbanes-Oxley Act of 2002. Such certifications contain no
qualifications or exceptions to the matters certified therein (other than such
qualifications or exceptions that are permitted under the Exchange Act and the
rules promulgated thereunder) and have not been modified or withdrawn; and
neither the

                                      -6-
<PAGE>

Company nor any of its officers has received notice from any governmental entity
questioning or challenging the accuracy, completeness, form or manner of filing
or submission of such certifications. Without limiting the foregoing, the
Company is in compliance with any applicable requirements of the Sarbanes-Oxley
Act of 2002 and the rules and regulations promulgated thereunder, as amended,
that are currently in effect, except where such noncompliance would not have or
reasonably be expected to result in a Material Adverse Effect or which would not
reasonably be expected to have a Material Adverse Effect on the transactions
contemplated by this Agreement.

                        (3) Financial Statements. The financial statements of
the Company included in the SEC Documents (1) comply in all material respects
with the rules and regulations of the SEC with respect thereto as were in effect
at the time of filing and (2) present fairly, in accordance with United States
generally accepted accounting principles ("GAAP"), consistently applied, the
consolidated financial position of the Company as of the dates indicated
therein, and the consolidated results of its operations and cash flows for the
periods therein specified, subject, in the case of unaudited consolidated
financial statements for interim periods, to normal, immaterial year-end audit
adjustments.

            (m) Absence of Certain Changes Since the Balance Sheet Date. Since
September 30, 2005, the business and operations of the Company have been
conducted in the ordinary course consistent with past practice, and there has
not been:

                  (i) any declaration, setting aside or payment of any dividend
or other distribution of the assets of the Company with respect to any shares of
capital stock of the Company or any repurchase, redemption or other acquisition
by the Company of any outstanding shares of the Company's capital stock;

                  (ii) any damage, destruction or loss to the Company's business
or assets, whether or not covered by insurance, except for such occurrences,
individually and collectively, that have not had, and would not reasonably be
expected to have, a Material Adverse Effect;

                  (iii) any waiver by the Company of a valuable right or of a
material debt owed to it, except for such waivers, individually and
collectively, that have not had, and would not reasonably be expected to have, a
Material Adverse Effect;

                  (iv) any material change or amendment to, or any waiver of any
material right under a material contract or arrangement by which the Company or
any of its assets or properties is bound or subject;

                  (v) any change by the Company in its accounting principles,
methods or practices or in the manner in which it keeps its accounting books and
records, except any such change required by a change in GAAP or by the SEC; or

                  (vi) any other event or condition of any character, except for
such events and conditions that have not resulted, and are not expected to
result, either individually or collectively, in a Material Adverse Effect.

                                      -7-
<PAGE>

            (n) Intellectual Property. The Company owns or possesses sufficient
rights to use all patents, patent rights, inventions, trade secrets, know-how,
trademarks, service marks, trade names, licenses, copyrights or other
information (collectively, "INTELLECTUAL PROPERTY"), which are necessary to
conduct their businesses as currently conducted, except where the failure to own
or possess such sufficient rights would not reasonably be expected to result,
either individually or in the aggregate, in a Material Adverse Effect. The
Company has not received any written notice of, and has no actual knowledge of,
any infringement of or conflict with asserted rights of others with respect to
any Intellectual Property which, either individually or in the aggregate, if the
subject of an unfavorable decision, ruling or finding, would reasonably be
expected to have a Material Adverse Effect, and to the Company's knowledge, none
of the patent rights owned or licensed by the Company are unenforceable or
invalid.

            (o) Registration Rights. Except as provided in Section 5 herein,
effective upon the Closing, the Company is not currently subject to any
agreement providing any person or entity any rights (including piggyback
registration rights) to have any securities of the Company registered with the
SEC or registered or qualified with any other governmental authority.

            (p) Title to Property and Assets. The properties and assets of the
Company are owned by the Company free and clear of all mortgages, deeds of
trust, liens, charges, encumbrances and security interests, except for (i)
statutory liens for the payment of current taxes that are not yet delinquent and
(ii) liens, encumbrances and security interests that arise in the ordinary
course of business and do not in any material respect affect the business of the
Company as currently conducted. With respect to the property and assets it
leases, the Company is in compliance with such leases in all material respects.

            (q) Taxes. The Company has filed or has valid extensions of the time
to file all necessary federal, state, and foreign income and franchise tax
returns due prior to the date hereof and has paid or accrued all taxes shown as
due thereon, and the Company has no knowledge of any material tax deficiency
which has been or might be asserted or threatened against it.

            (r) Insurance. The Company maintains insurance of the types and in
the amounts that the Company reasonably believes are prudent and adequate for
its business, all of which insurance is currently in effect.

            (s) Labor Relations. No material labor dispute exists or, to the
knowledge of the Company, is imminent with respect to any of the employees of
the Company.

            (t) Internal Accounting Controls. The Company maintains a system of
internal accounting controls sufficient to provide reasonable assurance that (i)
transactions are executed in accordance with management's general or specific
authorizations, (ii) transactions are recorded as necessary to permit
preparation of financial statements in conformity with GAAP and to maintain
asset accountability, (iii) access to assets is permitted only in accordance
with management's general or specific authorization, and (iv) the recorded
accountability for assets is compared with the existing assets at reasonable
intervals and appropriate action is taken with respect to any differences.

                                      -8-
<PAGE>

            (u) Transactions With Officers and Directors. None of the officers
or directors of the Company has entered into any transaction with the Company or
that would be required to be disclosed pursuant to Item 404(a), (b) or (c) of
Regulation S-K of the SEC.

            (v) General Solicitation. Neither the Company nor any other Person
(as defined below) authorized by the Company to act on its behalf has engaged in
a general solicitation or general advertising (within the meaning of Regulation
D) of investors with respect to offers or sales of the Purchased Securities. For
purposes of this Agreement, "PERSON" means an individual or corporation, trust,
incorporated or unincorporated association, joint venture, limited liability
company, joint stock company, government (or an agency or subdivision thereof)
or other entity of any kind.

            (w) Registration Statement Matters. The Company must use a Form S-1
registration statement for the resale of Registrable Shares (as defined below)
by the Purchasers as the Common Stock of the Company is trading on the NASD
Over-The-Counter Bulletin Board. Assuming the completion and timely delivery of
the Registration Statement/Suitability Questionnaire, attached hereto as
Appendix II (the "REGISTRATION STATEMENT QUESTIONNAIRE"), by each Purchaser to
the Company, the Company is not aware of any facts or circumstances that would
prohibit or delay the preparation and filing of a Form S-1 registration
statement with respect to the Registrable Shares (as defined below).

            (x) No Integrated Offering. Neither the Company, nor any Affiliate
(as hereafter defined) of the Company, nor any person acting on its behalf has,
directly or indirectly, made any offers or sales of any security or solicited
any offers to buy any security, under circumstances that would cause this
offering of the Purchased Securities to be integrated with prior offerings by
the Company for purposes of the Securities Act, any applicable state securities
laws or any applicable stockholder approval provisions, nor will the Company
take any action or steps that would cause the offering of the Purchased
Securities to be integrated with other offerings.

      For the purposes of this Agreement, an "AFFILIATE" of any specified Person
means any other Person directly or indirectly controlling, controlled by or
under direct or indirect common control with such specified Person. For purposes
of this definition, "CONTROL" means the power to direct the management and
policies of such person or firm, directly or indirectly, whether through the
ownership of voting securities, by contract or otherwise.

            (y) Market. The Company has not taken and will not take, directly or
indirectly, any action designed to or that might reasonably be expected to cause
or result in stabilization or manipulation of the price of the Common Stock of
the Company to facilitate the sale or resale of the Purchased Securities.

            (z) Investment Company. The Company is not an "investment company"
within the meaning of such term under the Investment Company Act of 1940, as
amended, and the rules and regulations of the SEC thereunder.

            (aa) Application of Anti-Takeover Provisions. There is no control
share acquisition, business combination, poison pill (including any distribution
under a rights

                                      -9-
<PAGE>

agreement) or other similar anti-takeover provision under the Company's
Certificate of Incorporation (or similar charter documents) that would become
applicable to the Purchasers as a result of the issuance of the Company Shares
and Warrant Shares.

            (bb) Trading and Registration Matters. The Common Stock of the
Company is eligible for trading on the NASD Over-The-Counter Bulletin Board
under the ticker symbol "NWBT.OB." The Company has taken no action designed to
terminate, or likely to have the effect of terminating, the registration of the
Common Stock under the Exchange Act.

      4. REPRESENTATIONS, WARRANTIES AND CERTAIN AGREEMENTS OF THE PURCHASERS.
Each Purchaser, severally and not jointly, hereby represents and warrants to the
Company, and agrees that:

            (a) Organization. The Purchaser has all corporate, limited liability
company, partnership, trust or individual, as the case may be, power and
authority required to enter into this Agreement and the other agreements,
instruments and documents contemplated hereby, and to consummate the
transactions contemplated hereby and thereby.

            (b) Due Authorization. All corporate, limited liability company,
partnership, trust or individual, as the case may be, action on the part of the
Purchaser necessary for the authorization, execution, delivery of and the
performance of all obligations of the Purchaser under this Agreement have been
taken and no further consent or authorization of the Purchaser is necessary, and
this Agreement constitutes the Purchaser's legal, valid and binding obligation,
enforceable in accordance with its terms, except (i) as may be limited by (1)
applicable bankruptcy, insolvency, reorganization or other laws of general
application relating to or affecting the enforcement of creditors' rights
generally and (2) the effect of rules of law governing the availability of
equitable remedies and (ii) as rights to indemnity or contribution may be
limited under federal or state securities laws or by principles of public policy
thereunder.

            (c) Litigation. There is no Action pending to which such Purchaser
is a party that is reasonably likely to prevent, enjoin, alter or delay the
transactions contemplated by this Agreement.

            (d) Purchase for Own Account. The Purchased Securities are being
acquired for investment for the Purchaser's own account, not as a nominee or
agent, in the ordinary course of business, and not with a view to the public
resale or distribution thereof within the meaning of the Securities Act. The
Purchaser also represents that it has not been formed for the specific purpose
of acquiring the Purchased Securities. The Purchaser does not have any agreement
or understanding, direct or indirect, with any other Person to sell or otherwise
distribute the Purchased Securities. Notwithstanding the foregoing, the parties
hereto acknowledge the Purchaser's right at all times to sell or otherwise
dispose of all or any part of such securities in compliance with applicable
federal and state securities laws and as otherwise contemplated by this
Agreement.

            (e) Investment Experience. The Purchaser understands that the
purchase of the Purchased Securities involves substantial risk. The Purchaser
has experience as an investor in securities of companies and acknowledges that
it can bear the economic risk of its investment

                                      -10-
<PAGE>

in the Purchased Securities and has such knowledge and experience in financial
or business matters that it is capable of evaluating the merits and risks of
this investment in the Purchased Securities and protecting its own interests in
connection with this investment.

            (f) Accredited Purchaser Status. The Purchaser is an "accredited
investor" within the meaning of Regulation D.

            (g) Reliance Upon Purchaser's Representations. The Purchaser
understands that the sale of the Purchased Securities to it will not be
registered under the Securities Act on the ground that such issuance and sale
will be exempt from registration under the Securities Act, and that the
Company's reliance on such exemption is based on each Purchaser's
representations set forth herein.

            (h) Receipt of Information. The Purchaser has had an opportunity to
ask questions and receive answers from the Company regarding the terms and
conditions of the sale of the Purchased Securities and the business, properties,
prospects and financial condition of the Company and to obtain any additional
information requested and has received and considered all information it deems
relevant to make an informed decision to purchase the Purchased Securities.
Neither such inquiries nor any other investigation conducted by or on behalf of
such Purchaser or its representatives or counsel shall modify, amend or affect
such Purchaser's right to rely on the truth, accuracy and completeness of such
information and the Company's representations and warranties contained in this
Agreement.

            (i) Restricted Securities and Restrictions on Transfer.

                  (i) The Purchaser understands that the Purchased Securities
and the Warrant Shares have not been registered under the Securities Act and
will not sell, offer to sell, assign, pledge, hypothecate or otherwise transfer
any of the Purchased Securities or the Warrant Shares (except as permitted in
Section 4(j) below) unless (i) pursuant to an effective registration statement
under the Securities Act, (ii) the Purchaser provides a reasonably acceptable
legal opinion to the Company, to the effect that a sale, assignment, pledge,
hypothecation or other transfer of the Purchased Securities or the Warrant
Shares, as the case may be, may be made without registration under the
Securities Act and the transferee agrees to be bound by the terms and conditions
of this Agreement, (iii) the Purchaser provides the Company a "no action" letter
from the SEC to the effect that the transfer of the Purchased Securities or the
Warrant Shares, as the case may be, without registration will not result in a
recommendation by the Staff of the SEC that enforcement action by taken with
respect thereto, (iv) the Purchaser provides the Company with reasonable
assurances (in the form of seller and broker representation letters) that the
Purchased Securities or the Warrant Shares, as the case may be, can be sold
pursuant to Rule 144 promulgated under the Securities Act ("RULE 144"), (v) the
Purchaser provides the Company with reasonable assurances (in the form of seller
representation letters) that the Purchased Securities or the Warrant Shares, as
the case may be, can be sold pursuant to Rule 144(k) promulgated under the
Securities Act following the applicable holding period or (vi) pursuant to any
other exception contained in the Securities Act provided that the Purchaser
provides a reasonably acceptable legal opinion to the Company. Notwithstanding
anything to the contrary contained in this Agreement, including but not limited
to in Section 5(c)(i) below, the Purchaser may transfer the Purchased Securities
or the Warrant Shares to its Affiliates provided that (i) the

                                      -11-
<PAGE>

Purchaser provides the Company with a reasonably acceptable legal opinion, (ii)
such Affiliate is an "accredited investor" under Regulation D and (iii) each
such Affiliate agrees to be bound by the terms and conditions of this Agreement,
and in particular, confirms to the Company that all of the representations set
forth in Section 4 of this Agreement are true and correct as to such Affiliate
as of the date of the transfer to such Affiliate.

                  (ii) Prior to any proposed transfer pursuant to clause (ii),
(iii), (iv), (v) or (vi) in Section 4(i) above, the Purchaser shall give written
notice to the Company of such Purchaser's intention to effect such transfer.
Each such notice shall describe the manner and circumstances of the proposed
transfer in sufficient detail, and shall be accompanied by the applicable legal
opinion, "no action" letter or seller and broker representation letters.

                  (iii) Notwithstanding the foregoing provisions of this Section
4(i), no registration statement, legal opinion or "no action" letter shall be
necessary for a transfer of the Purchased Securities or the Warrant Shares (1)
by a Purchaser that is a partnership to a partner of such partnership or a
retired partner of such partnership who retires after the date of this
Agreement, (2) by a Purchaser that is a limited liability company to a member of
such limited liability company, (3) by a Purchaser that is a partnership or
limited liability company to the estate of any partner, retired partner, or
member thereof or (4) by any partner or member of a Purchaser that is a
partnership or limited liability company by gift, will or intestate succession
to such partner or member's spouse or to the siblings, lineal descendants,
ancestors of such partner or member or his or her spouse.

            (j) Legends.

                  (i) The Purchaser agrees that, to the extent necessary, the
certificates for the Purchased Shares and the Warrant Shares shall bear the
following legend:

            "THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
            REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
            "SECURITIES ACT") OR ANY APPLICABLE STATE SECURITIES LAWS, AND MAY
            NOT BE SOLD OR TRANSFERRED UNLESS (I) A REGISTRATION STATEMENT
            COVERING SUCH SECURITIES IS EFFECTIVE UNDER THE SECURITIES ACT OR
            (II) THE TRANSACTION IS EXEMPT FROM REGISTRATION UNDER THE
            SECURITIES ACT AND, IF THE COMPANY REQUESTS, AN OPINION SATISFACTORY
            TO THE COMPANY TO SUCH EFFECT HAS BEEN RENDERED BY COUNSEL."

      Certificates evidencing the Purchased Shares and the Warrant Shares shall
not contain any legend (i) while a registration statement (including the
Registration Statement) covering the resale of such security is effective under
the Securities Act, (ii) following any sale of such Purchased Shares or the
Warrant Shares pursuant to Rule 144, (iii) if such Purchased Shares or the
Warrant Shares are eligible for sale under Rule 144(k) or (iv) if such legend is
not required under applicable requirements of the Securities Act (including
judicial interpretations and pronouncements issued by the Staff of the SEC). The
Company shall cause its counsel to issue a

                                      -12-
<PAGE>

legal opinion to the Company's transfer agent promptly after the date on which
the Registration Statement is declared effective (the "EFFECTIVE DATE") if such
legal opinion is required by the Company's transfer agent to effect the removal
of the legend hereunder. If all or any portion of a Purchased Warrant is
exercised at a time when there is an effective registration statement to cover
the resale of the Warrant Shares, such Warrant Shares shall be issued free of
all legends. The Company agrees that following the Effective Date or at such
time as such legend is no longer required under this Section 4(j), it will, no
later than five (5) Business Days following the delivery by a Purchaser to the
Company or to the Company's transfer agent of a certificate representing
Purchased Shares or the Warrant Shares, as the case may be, issued with a
restrictive legend, deliver or cause to be delivered to such Purchaser a
certificate representing such Purchased Shares or the Warrant Shares, as the
case may be, that is free from all restrictive and other legends. The Company
may not make any notation on its records or give instructions to any transfer
agent of the Company that enlarge the restrictions on transfer set forth in
Section 4(i) or this Section 4(j).

      Each Purchaser, severally and not jointly with the other Purchasers,
agrees that the removal of the restrictive legend from certificates representing
the Purchased Shares or the Warrant Shares as set forth in this Section 4(j) is
predicated upon the Purchaser's covenant that the Purchaser only will sell any
Purchased Shares or Warrant Shares pursuant to either the registration
requirements of the Securities Act, including any applicable prospectus delivery
requirements, or an exemption therefrom.

      In addition, the Purchaser agrees that the Company may place stop transfer
orders with its transfer agent with respect to such certificates in order to
implement the restrictions on transfer set forth in this Agreement. The
appropriate portion of the legend and the stop transfer orders will be removed
promptly upon delivery to the Company of such satisfactory evidence as
reasonably may be required by the Company that such legend or stop transfer
orders are not required to ensure compliance with the Securities Act.

                  (ii) The Purchaser agrees that the Purchased Warrants shall
bear the following legend:

            "THIS WARRANT AND THE SECURITIES ISSUABLE UPON EXERCISE HEREOF HAVE
            NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED
            (THE "SECURITIES ACT") OR ANY APPLICABLE STATE SECURITIES LAWS, AND
            MAY NOT BE SOLD OR TRANSFERRED UNLESS (I) A REGISTRATION STATEMENT
            COVERING SUCH SECURITIES IS EFFECTIVE UNDER THE SECURITIES ACT OR
            (II) THE TRANSACTION IS EXEMPT FROM REGISTRATION UNDER THE
            SECURITIES ACT AND, IF THE COMPANY REQUESTS, AN OPINION SATISFACTORY
            TO THE COMPANY TO SUCH EFFECT HAS BEEN RENDERED BY COUNSEL."

            (k) Questionnaires. The Purchaser has completed or caused to be
completed the Stock Certificate Questionnaire and the Registration Statement
Questionnaire for use in preparation of the Registration Statement (as defined
in Section 5(a) below), and the answers to

                                      -13-
<PAGE>

such questionnaires are true and correct as of the date of this Agreement;
provided, that the Purchasers shall be entitled to update such information by
providing written notice thereof to the Company before the effective date of the
Registration Statement.

            (l) Restrictions on Short Sales. Neither the Purchaser nor any
Affiliate of such Purchaser which (i) had knowledge of the transactions
contemplated hereby, (ii) has or shares discretion relating to such Purchaser's
investments or trading or information concerning such Purchaser's investments,
including in respect of the Purchased Securities, or (iii) is subject to such
Purchaser's review or input concerning such Affiliate's investments or trading,
has or will, directly or indirectly, during the period beginning on the date on
which C.E. Unterberg, Towbin, financial advisor to the Company, first contacted
such Purchaser regarding the transactions contemplated by this Agreement until
the time of the filing of the Current Report of Form 8-K required by Section
9(m), engage in (1) any "short sales" (as such term is defined in Rule 3b-3
promulgated under the Exchange Act) of the Common Stock, including, without
limitation, the maintaining of any short position with respect to, establishing
or maintaining a "put equivalent position" (within the meaning of Rule 16a-1(h)
under the Exchange Act) with respect to, entering into any swap, derivative
transaction or other arrangement (whether any such transaction is to be settled
by delivery of Common Stock, other securities, cash or other consideration) that
transfers to another, in whole or in part, any economic consequences or
ownership, or otherwise dispose of, any of the Purchased Securities or the
Warrant Shares by the Purchaser or (2) any hedging transaction which establishes
a net short position with respect to the Purchased Securities (clauses (1) and
(2) together, a "SHORT SALE"); except for (A) Short Sales by the Purchaser or
Affiliate of such Purchaser which was, prior to the date on which such Purchaser
was first contacted by C.E. Unterberg, Towbin regarding the transactions
contemplated by this Agreement, a market maker for the Common Stock, provided
that such Short Sales are in the ordinary course of business of such Purchaser
or Affiliate of such Purchaser and are in compliance with the Securities Act,
the rules and regulations of the Securities Act and such other securities laws
as may be applicable, (B) Short Sales by the Purchaser or an Affiliate of such
Purchaser which by virtue of the procedures of such Purchaser are made without
knowledge of the transactions contemplated by this Agreement or (C) Short Sales
by the Purchaser or an Affiliate of such Purchaser to the extent that such
Purchaser or Affiliate of such Purchaser is acting in the capacity of a
broker-dealer executing unsolicited third-party transactions.

            (m) Independent Investment. The Purchaser has not agreed to act with
any other Purchaser for the purpose of acquiring, holding or disposing of any of
the Purchased Securities or the Warrant Shares for purposes of Section 13(d) of
the Exchange Act, and such Purchaser is acting independently with respect to its
investment in the Purchased Securities.

            (n) Confidentiality. The Purchaser agrees to use any information it
receives in the course of and in connection with the transactions contemplated
under this Agreement for the sole purpose of evaluating a possible investment in
the Purchased Securities and the Purchaser hereby acknowledges that it is
prohibited from reproducing or distributing any such information, this
Agreement, or any other offering materials provided by the Company or any of its
Affiliates in connection with the Purchaser's consideration of its investment in
the Company, in whole or in part, or divulging or discussing any of their
contents except to its advisors and representatives for the purpose of
evaluating such investment. The foregoing agreements shall not apply to any

                                      -14-
<PAGE>

information that (i) is or becomes publicly available through no fault of the
Purchaser, (ii) was already known to the Purchaser prior to its disclosure by
the Company or any of its Affiliates to the Purchasers, as evidenced by
documentation or other evidence reasonably satisfactory to the Company, (iii) is
or becomes available to the Purchaser on a non-confidential basis from a source
other than the Company or any of its Affiliates (so long as the Purchaser is not
aware such disclosure is in breach of a confidentiality obligation to the
Company), (iv) is independently developed by the Purchaser's personnel without
access to or use of the confidential information received from the Company or
any of its Affiliates, as evidenced by documentation or other evidence
reasonably satisfactory to the Company or (v) is legally required to be
disclosed by the Purchaser under operation of law or judicial or other
governmental order; provided, however, that if the Purchaser is requested or
ordered to disclose any such information pursuant to any court or other
governmental order or any other applicable legal procedure, it shall provide the
Company with reasonably prompt notice of any such request or order to enable the
Company to seek an appropriate protective order and shall provide the Company
with reasonable assistance in obtaining such protective order at the Company's
sole expense.

      5. FORM D FILING; REGISTRATION; COMPLIANCE WITH THE SECURITIES ACT.

            (a) Form D Filing; Registration of the Purchased Securities and
Warrant Shares. The Company hereby agrees that it shall:

                  (i) file in a timely manner a Form D relating to the sale of
the Purchased Securities under this Agreement, pursuant to Regulation D;

                  (ii) prepare and file with the SEC as soon as practicable and
in no event later than forty-five (45) days following the Closing Date the
("REQUIRED FILING DATE"), a registration statement on Form S-1 or such other
form that is available to the Company under the Securities Act (the
"REGISTRATION STATEMENT"), to enable the resale of the Purchased Securities
(together with any shares of Common Stock issued as a dividend or other
distribution with respect to, or in exchange for, or in replacement of, the
Purchased Shares or the Warrant Shares, the "REGISTRABLE SHARES") by the
Purchasers from time to time. The Company shall use all commercially reasonable
efforts to cause the Registration Statement (x) to be declared effective as
promptly as possible after filing, but in any event, no later than the 120th day
following the Closing Date (the "REQUIRED EFFECTIVE DATE"), or, in the event of
a review of the Registration Statement by the SEC, the Required Effective Date
will be no later than the 150th day following the Closing Date and (y) to remain
continuously effective until the earlier of (1) the second anniversary of the
effective date of the Registration Statement, (2) the date on which all
Registrable Shares purchased by the Purchasers pursuant to this Agreement have
been sold thereunder or (3) the date on which the Registrable Shares can be sold
by nonaffiliates of the Company pursuant to Rule 144(k) promulgated under the
Securities Act (the "REGISTRATION PERIOD"). If the Company receives notification
from the SEC that the Registration Statement will receive no action or review
from the SEC, then the Company will use its commercially reasonable efforts to
cause the Registration Statement become effective within five (5) Business Days
after such SEC notification.

                                      -15-
<PAGE>

                  (iii) prepare and file with the SEC such amendments (including
post-effective amendments) and supplements to the Registration Statement and the
Prospectus (as defined below) used in connection therewith as may be necessary
to keep the Registration Statement effective at all times until the end of the
Registration Period;

                  (iv) furnish to the Purchasers, with respect to the
Registrable Shares registered under the Registration Statement, such reasonable
number of copies of any prospectus in conformity with the requirements of the
Securities Act and such other documents as the Purchasers may reasonably request
in writing, in order to facilitate the public sale or other disposition of all
or any of the Registrable Shares by the Purchasers;

                  (v) use its commercially reasonable efforts to file documents
required of the Company for normal blue sky clearance in states specified in
writing by the Purchasers; provided, however, that the Company shall not be
required to qualify to do business or consent to service of process in any
jurisdiction in which it is not now so qualified or has not so consented;

                  (vi) promptly notify the Purchasers in writing of the
effectiveness of the Registration Statement on the same day the Registration
Statement has been declared effective;

                  (vii) promptly notify the Purchasers in writing of the
existence of any fact or the happening of any event, during the Registration
Period (but not as to the substance of any such fact or event), that makes any
statement of a material fact made in the Registration Statement, the Prospectus,
any amendment or supplement thereto, or any document incorporated by reference
therein untrue, or that requires the making of any additions to or changes in
the Registration Statement or the Prospectus in order to make such statements
not misleading; provided, however, that no notice by the Company shall be
required pursuant to this subsection (vii) in the event that the Company either
contemporaneously files a prospectus supplement to update the Prospectus or, if
applicable, a Current Report on Form 8-K or other appropriate Exchange Act
report that is incorporated by reference into the Registration Statement, which,
in either case, contains the requisite information with respect to such material
event that results in such Registration Statement no longer containing any such
untrue or misleading statements; and

                  (viii) bear all expenses in connection with the procedures
described in paragraphs (i) through (vii) of this Section 5(a) and the
registration of the Registrable Shares pursuant to the Registration Statement,
other than fees and expenses, if any, of legal counsel or other advisers to the
Purchasers or underwriting discounts, brokerage fees and commissions incurred by
the Purchasers, if any.

      It shall be a condition precedent to the obligations of the Company to
take any action pursuant to this Section 5(a) with respect to Registrable Shares
held by a Purchaser that such Purchaser shall timely furnish to the Company a
completed Registration Statement Questionnaire on or before the Closing Date and
such other written information regarding such Purchaser, the Registrable Shares
to be sold by such Purchaser and the intended method of disposition of the
Registrable Shares as the Company may deem necessary or advisable to effect the
registration of the Registrable Shares. The Purchasers shall update such
information as and when necessary by written notice to the Company.

                                      -16-
<PAGE>

            (b) Liquidated Damages.

                  (i) Delay in Filing or Effectiveness of Registration
Statement. In the event that the Registration Statement is not (A) filed by the
Required Filing Date or (B) declared effective by the Required Effective Date,
the Company shall pay to each Purchaser (except for any Purchaser whose failure
to provide information as required hereunder causes a delay in filing or
obtaining effectiveness) liquidated damages (in addition to the rights and
remedies available to each Purchaser under applicable law and this Agreement),
at a rate equal to one percent (1%) per month (pro rata on a 30-day basis) of
the total purchase price of the Purchased Securities purchased by such Purchaser
and still held by such Purchaser pursuant to this Agreement for the period from
and including the day following the Required Effective Date, until, but
excluding, the date the SEC declares the Registration Statement effective,
provided, however, that in no event shall the aggregate amount of all such
liquidated damages payable pursuant to this subsection (i) and subsection (ii)
below exceed ten percent (10%) of the total purchase price of the Purchased
Securities purchased by such Purchaser pursuant to this Agreement. Such
liquidated damages shall be payable in cash within ten (10) days of the end of
each one (1) month anniversary of (A) the Required Filing Date or (B) the day
following the Required Effective Date, as the case may be.

                  (ii) Lapse in Effectiveness of Registration Statement. In the
event that the Registration Statement is filed and declared effective but,
during the Registration Period, the Registration Statement ceases to be
effective or useable or the prospectus included in the Registration Statement
(the "PROSPECTUS", as amended or supplemented by any prospectus supplement and
by all other amendments thereto and all material incorporated by reference in
such Prospectus) ceases to be usable, in either case, in connection with resales
of Registrable Shares, without such lapse being cured within ten (10) Business
Days (the "CURE PERIOD") by a post-effective amendment to the Registration
Statement, a supplement to the Prospectus or a report filed with the SEC
pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act that cures
such lapse, then the Company shall pay to each Purchaser liquidated damages (in
addition to the rights and remedies available to each Purchaser under applicable
law and this Agreement), for the period from and including the first day
following the expiration of the Cure Period until, but excluding, the earlier of
(1) the date on which such failure is cured and (2) the date on which the
Registration Period expires, at a rate equal to one percent (1%) per month (pro
rata on a 30-day basis) of the total purchase price of the Purchased Securities
purchased by such Purchaser and still held by such Purchaser pursuant to this
Agreement, provided, however, that in no event shall the aggregate amount of all
such liquidated damages payable pursuant to this subsection (ii) and subsection
(i) above exceed ten percent (10%) of the total purchase price of the Purchased
Securities purchased by such Purchaser pursuant to this Agreement. Such
liquidated damages shall be payable in cash within ten (10) days of the end of
each one (1) month anniversary of the expiration of the Cure Period.

            (c) Transfer of Registrable Shares After Registration; Suspension.

                  (i) The Purchasers agree that they will not offer to sell or
make any sale, assignment, pledge, hypothecation or other transfer with respect
to the Registrable Shares that would constitute a sale within the meaning of the
Securities Act except pursuant to either (1) the Registration Statement in the
manner described in the "Plan of Distribution" therein, (2) Rule

                                      -17-
<PAGE>

144 of the Securities Act or (3) any other exemption from registration under the
Securities Act, and that they will promptly notify the Company of any changes in
the information set forth in the Registration Statement after it is prepared
regarding the Purchaser or its plan of distribution to the extent required by
applicable law.

                  (ii) In addition to any suspension rights under paragraph
(iii) below, upon the happening of any pending corporate development, public
filing with the SEC or similar event that, in the judgment of the Board of
Directors, renders it advisable to suspend the use of the Prospectus or upon the
request by an underwriter in connection with an underwritten public offering of
the Company's securities, the Company may, on not more than two (2) occasions
for not more than forty-five (45) days on each such occasion, suspend use of the
Prospectus on written notice to each Purchaser (which notice will not disclose
the content of any material non-public information and will indicate the date of
the beginning and end of the intended period of suspension, if known), in which
case each Purchaser shall discontinue any disposition of Registrable Shares
covered by the Registration Statement or Prospectus until copies of a
supplemented or amended Prospectus are distributed to the Purchasers or until
the Purchasers are advised in writing by the Company that sales of Registrable
Shares under the applicable Prospectus may be resumed and have received copies
of any additional or supplemental filings that are incorporated or deemed
incorporated by reference in any such Prospectus. The suspension and notice
thereof described in this Section 5(c)(ii) shall be held by each Purchaser in
strictest confidence and shall not be disclosed by such Purchaser.

                  (iii) Subject to paragraph (iv) below, in the event of: (1)
any request by the SEC or any other federal or state governmental authority
during the Registration Period for amendments or supplements to a Registration
Statement or related prospectus or for additional information; (2) the issuance
by the SEC or any other federal or state governmental authority of any stop
order suspending the effectiveness of a Registration Statement or the initiation
of any proceedings for that purpose; (3) the receipt by the Company of any
notification with respect to the suspension of the qualification or exemption
from qualification of any of the Registrable Shares for sale in any jurisdiction
or the initiation of any proceeding for such purpose; or (4) any event or
circumstance which necessitates the making of any changes in the Registration
Statement or Prospectus, or any document incorporated or deemed to be
incorporated therein by reference, so that, in the case of the Registration
Statement, it will not contain any untrue statement of a material fact or any
omission to state a material fact required to be stated therein or necessary to
make the statements therein not misleading, and that in the case of the
Prospectus, it will not contain any untrue statement of a material fact or any
omission to state a material fact required to be stated therein or necessary to
make the statements therein, in the light of the circumstances under which they
were made, not misleading, then the Company shall deliver a certificate in
writing to the Purchasers (the "SUSPENSION NOTICE") to the effect of the
foregoing (which notice will not disclose the content of any material non-public
information and will indicate the date of the beginning and end of the intended
period of suspension, if known), and, upon receipt of such Suspension Notice,
the Purchasers will discontinue disposition of Registrable Shares covered by to
the Registration Statement or Prospectus (a "SUSPENSION") until the Purchasers'
receipt of copies of a supplemented or amended Prospectus prepared and filed by
the Company, or until the Purchasers are advised in writing by the Company that
the current Prospectus may be used and have received copies of any additional or
supplemental filings that are incorporated or deemed incorporated by reference
in any such prospectus. In the event of

                                      -18-
<PAGE>

any Suspension, the Company will use its commercially reasonable efforts to
cause the use of the Prospectus so suspended to be resumed as soon as possible
after delivery of a Suspension Notice to the Purchasers. The Suspension and
Suspension Notice described in this Section 5(c)(iii) shall be held in strictest
confidence by each Purchaser and shall not be disclosed by such Purchaser.

                  (iv) Provided that a Suspension is not then in effect, the
Purchasers may sell Registrable Shares under the Registration Statement,
provided that the selling Purchaser arranges for delivery of a current
Prospectus to the transferee of such Registrable Shares to the extent such
delivery is required by applicable law.

                  (v) In the event of a sale of Registrable Shares by a
Purchaser, such Purchaser must also deliver to the Company's transfer agent,
with a copy to the Company, a certificate of subsequent sale reasonably
satisfactory to the Company, so that ownership of the Registrable Shares may be
properly transferred. The Company will cooperate to facilitate the timely
preparation and delivery of certificates (unless otherwise required by
applicable law) representing Registrable Shares sold.

            (d) Indemnification. For the purpose of this Section 5(d), the term
"REGISTRATION STATEMENT" shall include any preliminary or final Prospectus,
exhibit, supplement or amendment included in or relating to the Registration
Statement referred to in Section 5(a).

                  (i) Indemnification by the Company. The Company agrees to
indemnify and hold harmless each of the Purchasers, their respective officers,
directors, agents and employees, and each person, if any, who controls any
Purchaser within the meaning of the Securities Act, against any losses, claims,
damages, liabilities or expenses, joint or several, to which such Purchasers,
such officers, directors, agents or employees, or such controlling persons may
become subject, under the Securities Act, the Exchange Act or any other federal
or state statutory law or regulation, or at common law or otherwise (including
in settlement of any litigation, if such settlement is effected with the written
consent of the Company, which consent shall not be unreasonably withheld),
insofar as such losses, claims, damages, liabilities or expenses (or actions in
respect thereof as contemplated below) arise out of or are based upon any untrue
statement or alleged untrue statement of any material fact contained in the
Registration Statement, the Prospectus, or any amendment or supplement to the
Registration Statement or Prospectus, or arise out of or are based upon (i) the
omission or alleged omission to state in any of them a material fact required to
be stated therein or necessary to make the statements in any of them, in light
of the circumstances under which they were made, not misleading or (ii) any
inaccuracy in or breach of the representations and warranties or covenants made
by the Company herein, and will reimburse each Purchaser, each of its respective
directors, officers, agents and employees, and each such controlling person for
any reasonable out-of-pocket legal and other expenses incurred by such
Purchaser, such directors, officers, agents or employees, or such controlling
persons in connection with investigating, defending, settling, compromising or
paying any such loss, claim, damage, liability, expense or action; provided,
however, that the Company will not be liable for any such case to the extent
that any such loss, claim, damage, liability, expense or action arises out of or
is based upon (1) an untrue statement or alleged untrue statement or omission or
alleged omission in the Registration Statement, the Prospectus or any amendment
to or supplement of the Registration Statement or the Prospectus made in
reliance upon and in conformity with written information furnished to the
Company by or on

                                      -19-
<PAGE>

behalf of the Purchaser demanding such indemnification expressly for use in the
Registration Statement or the Prospectus, (2) the failure of such Purchaser to
comply with the covenants and agreements contained in this Agreement respecting
resale of the Purchased Securities or the Warrant Shares or (3) any untrue
statement or omission of a material fact required to make such statement not
misleading in any Prospectus that is corrected in any subsequent Prospectus that
was delivered to such Purchaser before the pertinent sale or sales by such
Purchaser.

                  (ii) Indemnification by each Purchaser. Each Purchaser agrees,
severally and not jointly, to indemnify and hold harmless the Company, each of
the Company's directors, officers, agents and employees, and each person, if
any, who controls the Company within the meaning of the Securities Act, against
any losses, claims, damages, liabilities or expenses to which the Company, the
Company's directors, officers, agents or employees, or any controlling persons
may become subject, under the Securities Act, the Exchange Act, or any other
federal or state statutory law or regulation, or at common law or otherwise
(including in settlement of any litigation, if such settlement is effected with
the written consent of such Purchaser, which consent shall not be unreasonably
withheld) insofar as such losses, claims, damages, liabilities or expenses (or
actions in respect thereof as contemplated below) arise out of or are based upon
(i) any untrue or alleged untrue statement of any material fact contained in the
Registration Statement, the Prospectus, or any amendment or supplement thereto,
or the omission or alleged omission to state therein a material fact required to
be stated therein or necessary to make the statements therein not misleading, in
each case to the extent, but only to the extent, that such untrue statement or
alleged untrue statement or omission or alleged omission was made in the
Registration Statement, the Prospectus, or any amendment or supplement thereto,
in reliance upon and in conformity with written information furnished to the
Company by or on behalf of such Purchaser expressly for use therein, or (ii) any
inaccuracy in or breach of the representations, warranties or covenants made by
such Purchaser herein and such Purchaser will reimburse the Company, each of its
directors, officers, agents and employees, and any controlling persons for any
reasonable legal and other expenses incurred by the Company, its directors,
officers, agents or employees, or any controlling persons in connection with
investigating, defending, settling, compromising or paying any such loss, claim,
damage, liability, expense or action; provided, however, that such Purchaser
shall not be liable for any such untrue or alleged untrue statement or omission
or alleged omission with respect to which such Purchaser has delivered to the
Company in writing a correction of such untrue or alleged untrue statement or
omission or alleged omission, before the occurrence of the event from which such
loss, claim, damage, liability or expense was incurred. Notwithstanding the
provisions of this Section 5(d), such Purchaser shall not be liable for any
indemnification obligation under this Agreement in excess of the aggregate
amount of net proceeds received by such Purchaser from the sale of the
Registrable Shares pursuant to the Registration Statement.

                  (iii) Indemnification Procedure.

                        (1) Promptly after receipt by an indemnified party under
this Section 5(d) of notice of the threat or commencement of any action, such
indemnified party will, if a claim in respect thereof is to be made against an
indemnifying party under this Section 5(d), promptly notify the indemnifying
party in writing of the claim and provide to the indemnifying party copies of
all written documents relating to such threatened or commenced action; but the
omission so to notify the indemnifying party will not relieve it from any
liability which it may

                                      -20-
<PAGE>

have to any indemnified party for contribution or otherwise under the indemnity
agreement contained in this Section 5(d) or otherwise, to the extent it is not
prejudiced as a result of such failure.

                        (2) In case any such action is brought against any
indemnified party and such indemnified party seeks or intends to seek indemnity
from an indemnifying party, the indemnifying party will be entitled to
participate in, and, to the extent that it may wish, jointly with all other
indemnifying parties similarly notified, to assume the defense thereof with
counsel reasonably satisfactory to such indemnified party; provided, however,
that if the defendants in any such action include both the indemnified party and
the indemnifying party and the indemnified party shall have reasonably concluded
that there may be a conflict between the positions of the indemnifying party and
the indemnified party in conducting the defense of any such action or that there
may be legal defenses available to it or other indemnified parties that are
different from or additional to those available to the indemnifying party, the
indemnified party or parties shall have the right to select one separate counsel
to assume such legal defenses and to otherwise participate in the defense of
such action on behalf of such indemnified party or parties. Upon receipt of
notice from the indemnifying party to such indemnified party of its election so
to assume the defense of such action and approval by the indemnified party of
counsel, the indemnifying party will not be liable to such indemnified party
under this Section 5(d) for any legal or other expenses subsequently incurred by
such indemnified party in connection with the defense thereof unless:

                              a) the indemnified party shall have employed such
counsel in connection with the assumption of legal defenses in accordance with
the proviso to the preceding sentence (it being understood, however, that the
indemnifying party shall not be liable for the expenses of more than one
separate counsel, reasonably approved by such indemnifying party, representing
all of the indemnified parties who are parties to such action); or

                              b) the indemnifying party shall not have employed
counsel reasonably satisfactory to the indemnified party to represent the
indemnified party within a reasonable time after notice of commencement of the
action against the indemnified party, in each of which cases the reasonable
out-of-pocket fees and expenses of counsel for the indemnified party shall be at
the expense of the indemnifying party.

                  (iv) Contribution. If the indemnification provided for in this
Section 5(d) is required by its terms but is for any reason held to be
unavailable to, or is otherwise insufficient to hold harmless, an indemnified
party under this Section 5(d) with respect to any losses, claims, damages,
liabilities or expenses referred to in this Agreement, then each indemnifying
party shall contribute to the amount paid or payable by such indemnified party
as a result of any losses, claims, damages, liabilities or expenses referred to
in this Agreement:

                        (1) in such proportion as is appropriate to reflect the
relative faults of the Company and the Purchasers in connection with the
statements or omissions or inaccuracies in the representations and warranties in
this Agreement that resulted in such losses, claims, damages, liabilities or
expenses, as well as any other relevant equitable considerations, or

                                      -21-
<PAGE>

                        (2) if the allocation provided by clause (1) above is
not permitted by applicable law, in such proportion as is appropriate to reflect
not only the relative faults referred to in clause (1) above but also the
relative benefits received by the Company and the Purchasers from the sale of
the Purchased Securities.

      The respective relative benefits received by the Company on the one hand
and each Purchaser on the other shall be deemed to be in the same proportion as
the amount to which the consideration paid by such Purchaser to the Company
pursuant to this Agreement for the Registrable Shares purchased by such
Purchaser that were sold pursuant to the Registration Statement bears to the
difference (the "DIFFERENCE") between the amount such Purchaser paid for the
Registrable Shares that were sold pursuant to the Registration Statement and the
amount received by such Purchaser from such sale. The relative fault of the
Company and each Purchaser shall be determined by reference to, among other
things, whether the untrue or alleged untrue statement of a material fact or the
omission or alleged omission to state a material fact relates to information
supplied by the Company or by such Purchaser and the parties' relative intent,
knowledge, access to information and opportunity to correct or prevent such
statement or omission. The amount paid or payable by a party as a result of the
losses, claims, damages, liabilities and expenses referred to above shall be
deemed to include, subject to the limitations set forth in Section 5(d)(iii),
any reasonable legal or other fees or expenses incurred by such party in
connection with investigating or defending any such action or claim. The
provisions set forth in Section 5(d)(iii) with respect to the notice of the
threat or commencement of any threat or action shall apply if a claim for
contribution is to be made under this Section 5(d)(iv); provided, however, that
no additional notice shall be required with respect to any threat or action for
which notice has been given under Section 5(d)(iii) for purposes of
indemnification. The Company and each Purchaser agree that it would not be just
and equitable if contribution pursuant to this Section 5(d)(iv) were determined
solely by pro rata allocation (even if the Purchasers were treated as one entity
for such purpose) or by any other method of allocation which does not take
account of the equitable considerations referred to in this paragraph.
Notwithstanding the provisions of this Section 5(d)(iv), no Purchaser shall be
required to contribute any amount in excess of the amount by which the
Difference exceeds the amount of any damages that such Purchaser has otherwise
been required to pay by reason of such untrue or alleged untrue statement or
omission or alleged omission. No person guilty of fraudulent misrepresentation
(within the meaning of Section 11(f) of the Securities Act) shall be entitled to
contribution from any person who is not guilty of such fraudulent
misrepresentation. The Purchasers' obligations to contribute pursuant to this
Section 5(d)(iv) are several and not joint.

                  (v) Notwithstanding any of the foregoing provisions of this
Section 5(d), no party shall be entitled to indemnification against any
consequential damages.

            (e) Rule 144 Information. For two years after the date of this
Agreement, the Company shall file in a timely manner all reports required to be
filed by it under the Securities Act and the Exchange Act and the rules and
regulations promulgated thereunder and shall take such further action to the
extent required to enable the Purchasers to sell the Purchased Securities
pursuant to Rule 144 under the Securities Act (as such rule may be amended from
time to time).

      6. ADVISORY FEE. The Purchasers acknowledge that the Company intends to
pay to C.E. Unterberg, Towbin, as financial advisor, a fee in respect of the
sale of the Purchased

                                      -22-
<PAGE>

Securities. Each of the parties to this Agreement hereby represents that, on the
basis of any actions and agreements by it, there are no other brokers or finders
entitled to compensation in connection with the sale of the Purchased Securities
to the Purchasers. The Company shall indemnify and hold harmless the Purchasers
from and against all fees, commission or other payments owing by the Company to
C.E. Unterberg, Towbin or any other Person acting on behalf of the Company
hereunder. Each Purchaser shall, severally and not jointly, indemnify and hold
harmless the Company from and against all fees, commission or other payments
owing by such Purchasers to any Person, other than C.E. Unterberg, Towbin,
acting on behalf of the Purchasers hereunder.

      7. CONDITIONS TO THE PURCHASERS' OBLIGATIONS AT CLOSING. The obligations
of the Purchasers to consummate the transactions contemplated herein are subject
to the fulfillment or waiver, on or before the Closing, of each of the following
conditions:

            (a) Representations and Warranties True. Each of the representations
and warranties of the Company contained in Section 3 shall be true and correct
in all material respects on and as of the date hereof (provided, however, that
such qualification shall only apply to representations or warranties not
otherwise qualified by materiality) and on and as of the Closing Date with the
same effect as though such representations and warranties had been made as of
the Closing (except for representations and warranties that speak as of a
specific date).

            (b) Performance. The Company shall have performed and complied in
all material respects with all agreements, obligations and conditions contained
in this Agreement that are required to be performed or complied with by it on or
before the Closing and shall have obtained all approvals, consents and
qualifications necessary to complete the purchase and sale described herein;
provided, however, as provided in Section 2 hereof, the Company may furnish to
each Purchaser a facsimile copy of the warrant representing the Purchased
Warrant and of the stock certificate(s) representing the Purchased Shares
purchased by such Purchaser no later than the next Business Day following the
Closing Date, with the original stock certificate(s) to be delivered to such
Purchaser by overnight courier no later than the third (3rd) Business Day
following the Closing Date.

            (c) Company Compliance Certificate. The Company will have delivered
to the Purchasers a certificate signed on its behalf by its Chief Executive
Officer, dated as of the Closing Date, certifying that the conditions specified
in Sections 7(a) and 7(b) hereof have been fulfilled.

            (d) Agreement. The Company shall have executed and delivered to the
Purchasers this Agreement.

            (e) Securities Exemptions. The offer and sale of the Purchased
Securities to the Purchasers pursuant to this Agreement shall be exempt from the
registration requirements of the Securities Act and the registration and/or
qualification requirements of all applicable state securities laws.

                                      -23-
<PAGE>

            (f) Good Standing Certificate. The Company shall have delivered to
the Purchasers a certificate of the Secretary of State of the State of Delaware,
dated as of a date within five days of the date of the Closing, with respect to
the good standing of the Company.

            (g) Secretary's Certificate. The Company shall have delivered to the
Purchasers a certificate of the Company executed by the Company's Secretary,
dated as of the Closing Date, attaching and certifying to the truth and
correctness of (1) the Certificate of Incorporation, (2) the Bylaws and (3) the
resolutions adopted by the Company's Board of Directors in connection with the
transactions contemplated by this Agreement.

            (h) Opinion of Company Counsel. The Purchasers will have received an
opinion on behalf of the Company, dated as of the Closing Date, from Jim D.
Johnston, counsel to the Company, substantially in the form attached hereto as
Exhibit C.

            (i) No Statute or Rule Challenging Transaction. No statute, rule,
regulation, executive order, decree, ruling, injunction, action, proceeding or
interpretation shall have been enacted, entered, promulgated, endorsed or
adopted by any court or governmental authority of competent jurisdiction or any
self-regulatory organization or the staff of any of the foregoing, having
authority over the matters contemplated hereby which questions the validity of,
or challenges or prohibits the consummation of, any of the transactions
contemplated by this Agreement.

            (j) Other Actions. The Company shall have executed such
certificates, agreements, instruments and other documents, and taken such other
actions as shall be customary or reasonably requested by the Purchasers in
writing in connection with the transactions contemplated hereby.

      8. CONDITIONS TO THE COMPANY'S OBLIGATIONS AT CLOSING. The obligations of
the Company to consummate the transactions contemplated herein are subject to
the fulfillment or waiver, on or before the Closing, of each of the following
conditions:

            (a) Representations and Warranties True. Each of the representations
and warranties of the Purchasers contained in Section 4 shall be true and
correct in all material respects on and as of the date hereof (provided,
however, that such qualification shall only apply to representations and
warranties not otherwise qualified by materiality) and on and as of the Closing
Date with the same effect as though such representations and warranties had been
made as of the Closing (except for representations and warranties that speak as
of a specific date).

            (b) Performance. The Purchasers shall have performed and complied in
all material respects with all agreements, obligations and conditions contained
in this Agreement that are required to be performed or complied with by them on
or before the Closing and shall have obtained all approvals, consents and
qualifications necessary to complete the purchase and sale described herein.

            (c) Agreement. Each Purchaser shall have executed and delivered to
the Company this Agreement (and Appendix I and II hereto).

                                      -24-
<PAGE>

            (d) Securities Exemptions. The offer and sale of the Purchased
Securities to the Purchasers pursuant to this Agreement shall be exempt from the
registration requirements of the Securities Act and the registration and/or
qualification requirements of all applicable state securities laws.

            (e) Payment of Purchase Price. The Purchasers shall have delivered
to the Company by wire transfer of immediately available funds, full payment of
the purchase price for the Purchased Securities as specified in Section 1(b).

            (f) No Statute or Rule Challenging Transaction. No statute, rule,
regulation, executive order, decree, ruling, injunction, action, proceeding or
interpretation shall have been enacted, entered, promulgated, endorsed or
adopted by any court or governmental authority of competent jurisdiction or any
self-regulatory organization or the staff of any of the foregoing, having
authority over the matters contemplated hereby which questions the validity of,
or challenges or prohibits the consummation of, any of the transactions
contemplated by this Agreement.

            (g) Other Actions. The Purchasers shall have executed such
certificates, agreements, instruments and other documents, and taken such other
actions as shall be customary or reasonably requested by the Company in
connection with the transactions contemplated hereby.

      9. MISCELLANEOUS.

            (a) Successors and Assigns. The terms and conditions of this
Agreement will inure to the benefit of and be binding upon the respective
successors and permitted assigns of the parties. The Company shall not assign
this Agreement or any rights or obligations hereunder without the prior written
consent of the Purchasers holding at least a majority of the total aggregate
number of Purchased Shares and Warrant Shares then outstanding (excluding any
Purchased Shares or Warrant Shares sold to the public pursuant to Rule 144 or
otherwise). Any Purchaser may assign its rights under this Agreement to any
person to whom such Purchaser assigns or transfers any of the Purchased
Securities, provided that such transferee agrees in writing to be bound by the
terms and provisions of this Agreement, and such transfer is in compliance with
the terms and provisions of this Agreement and permitted by federal and state
securities laws.

            (b) Governing Law. This Agreement will be governed by and construed
and enforced under the internal laws of the State of New York, without reference
to principles of conflict of laws or choice of laws. EACH PARTY HEREBY
IRREVOCABLY WAIVES ANY RIGHT IT MAY HAVE, AND AGREES NOT TO REQUEST, A JURY
TRIAL FOR THE ADJUDICATION OF ANY DISPUTE HEREUNDER OR IN CONNECTION HEREWITH OR
ARISING OUT OF THIS AGREEMENT OR ANY TRANSACTION CONTEMPLATED HEREBY.

            (c) Survival. The representations and warranties of the Company
contained in Section 3 of this Agreement and of the Purchasers contained in
Section 4 of this Agreement shall survive until the fifth (5th) anniversary of
the Closing Date.

                                      -25-
<PAGE>

            (d) Counterparts. This Agreement may be executed in two or more
counterparts, each of which will be deemed an original, but all of which
together will constitute one and the same instrument.

            (e) Headings. The headings and captions used in this Agreement are
used for convenience only and are not to be considered in construing or
interpreting this Agreement. All references in this Agreement to sections,
paragraphs, exhibits and schedules will, unless otherwise provided, refer to
sections and paragraphs hereof and exhibits and schedules attached hereto, all
of which exhibits and schedules are incorporated herein by reference.

            (f) Notices. Any notices and other communications required or
permitted under this Agreement shall be in writing and shall be delivered (i)
personally by hand or by courier, (ii) mailed by United States first-class mail,
postage prepaid or (iii) sent by facsimile directed (A) if to any Purchaser, at
such Purchaser's address or facsimile number set forth on Schedule A to this
Agreement, or at such address or facsimile number as such Purchaser may
designate by giving at least ten (10) days' advance written notice to the
Company or (b) if to the Company, to its address or facsimile number set forth
below, or at such other address or facsimile number as the Company may designate
by giving at least ten (10) days' advance written notice to the Purchasers. All
such notices and other communications shall be deemed given upon actual receipt
or refusal of receipt.

      If to the Company:

                  Northwest Biotherapeutics, Inc.
                  18701 120th Avenue NE
                  Suite 101
                  Bothell, WA  98011
                  Tel:  (425) 608-3000
                  Fax:  (425) 608-3009
                  Attention:  President

      with a copy to:  Jim D. Johnston

                  11808 Northup Way, Suite W-190
                  Bellevue, WA 98005
                  Tel:  (425) 893-8273
                  Fax:  (425) 828-7756
                  Attention:  Jim D. Johnston

            (g) Amendments and Waivers. This Agreement may be amended and the
observance of any term of this Agreement may be waived only with the written
consent of the Company and the Purchasers holding at least a majority of the
total aggregate number of the Purchased Shares and Warrant Shares then
outstanding (excluding any shares then already sold to the public pursuant to
Rule 144 or otherwise). Any amendment effected in accordance with this Section
9(g) will be binding upon the Purchasers, the Company and their respective
successors and assigns.

            (h) Severability. If any provision of this Agreement is held to be
unenforceable under applicable law, such provision will be excluded from this
Agreement and

                                      -26-
<PAGE>

the balance of the Agreement will be interpreted as if such provision were so
excluded and will be enforceable in accordance with its terms.

            (i) Entire Agreement. This Agreement, together with all exhibits and
schedules hereto, constitute the entire agreement and understanding of the
parties with respect to the subject matter hereof and supersede any and all
prior negotiations, correspondence, agreements, understandings, duties or
obligations between the parties with respect to the subject matter hereof.

            (j) Further Assurances. From and after the date of this Agreement,
upon the request of the Company or the Purchasers, the Company and the
Purchasers will execute and deliver such instruments, documents or other
writings, and take such other actions, as may be reasonably necessary or
desirable to confirm and carry out and to effectuate fully the intent and
purposes of this Agreement.

            (k) Meaning of Include and Including. Whenever in this Agreement the
word "include" or "including" is used, it shall be deemed to mean "include,
without limitation" or "including, without limitation," as the case may be, and
the language following "include" or "including" shall not be deemed to set forth
an exhaustive list.

            (l) Fees, Costs and Expenses. Except as otherwise provided for in
this Agreement, all fees, costs and expenses (including attorneys' fees and
expenses) incurred by any party hereto in connection with the preparation,
negotiation and execution of this Agreement and the exhibits and schedules
hereto and the consummation of the transactions contemplated hereby and thereby
(including the costs associated with any filings with, or compliance with any of
the requirements of any governmental authorities), shall be the sole and
exclusive responsibility of such party.

            (m) 8-K Filing and Publicity. As soon as practicable following the
execution of this Agreement, but in no event later than 8:30 a.m., eastern time,
on the day following the Execution Date, the Company shall file a Current Report
on Form 8-K with the SEC describing the terms of the transactions contemplated
by this Agreement and attaching this Agreement and the press release referred to
below as exhibits to such filing (the "8-K FILING" including all attachments).
Neither the Company nor any Purchaser shall issue any press releases or any
other public statements with respect to the transactions contemplated by this
Agreement; provided, however, that the Company shall be entitled, without the
prior approval of any Purchaser, to issue any press release or make any other
public disclosure (including a press release (concerning the offering of the
Purchased Securities) pursuant to Rule 135(c) under the Securities Act) with
respect to such transactions (i) in substantial conformity with the 8-K Filing
and (ii) as is required by applicable laws and regulations; and, provided
further, that no such release may identify a Purchaser unless such Purchaser has
consented thereto in writing, or as required by law.

            (n) Waivers. No waiver by any party to this Agreement of any default
with respect to any provision, condition or requirement of this Agreement shall
be deemed to be a continuing waiver in the future or a waiver of any other
provision, condition or requirement

                                      -27-
<PAGE>

hereof, nor shall any delay or omission of any party to exercise any right
hereunder in any manner impair the exercise of any such right accruing to it
thereafter.

            (o) Stock Splits, Dividends and other Similar Events. The provisions
of this Agreement shall be appropriately adjusted to reflect any stock split,
stock dividend, reorganization or other similar event that may occur with
respect to the Company after the date hereof.

            (p) Remedies. In addition to being entitled to exercise all rights
provided herein or granted by law, including recovery of damages, each Purchaser
and the Company will be entitled to specific performance under this Agreement.
The parties agree that monetary damages may not be adequate compensation for any
loss incurred by reason of any breach of obligations described in the foregoing
sentence and hereby agrees to waive in any action for specific performance of
any such obligation the defense that a remedy at law would be adequate.

                  [Remainder of page intentionally left blank.]

                                      -28-
<PAGE>

      IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
the date and year first above written.

                                NORTHWEST BIOTHERAPEUTICS, INC.

                                By:_____________________________________________
                                   Name:  Alton Boynton
                                   Title: President

                      [PURCHASER SIGNATURE PAGES TO FOLLOW]

<PAGE>

                                SIGNATURE PAGE TO

                          SECURITIES PURCHASE AGREEMENT

                       DATED AS OF _________________, 2006

                                  BY AND AMONG

                         NORTHWEST BIOTHERAPEUTICS, INC.

                        AND EACH PURCHASER NAMED THEREIN

      The undersigned hereby executes and delivers to Northwest Biotherapeutics,
Inc., the Securities Purchase Agreement (the "AGREEMENT") to which this
signature page is attached effective as of the date of the Agreement, which
Agreement and signature sage, together with all counterparts of such Agreement
and signature pages of the other Purchasers named in such Agreement, shall
constitute one and the same document in accordance with the terms of such
Agreement.

                                Number of Purchased Shares Purchased:___________

                                Number of Purchased Warrants Purchased:_________

                                Total Number of Units Purchased:________________

                                ________________________________________________
                                "Purchaser"

                                Signature:______________________________________

                                Name:___________________________________________

                                Title:__________________________________________

                                Address:________________________________________
                                ________________________________________________

                                Telephone:______________________________________

                                Facsimile:______________________________________

                                E-mail:_________________________________________

                                Tax ID Number:__________________________________
<PAGE>
                                   SCHEDULE A

                             SCHEDULE OF PURCHASERS
<TABLE>
<CAPTION>
                                      Number of
                       Number of      Purchased   Total Number of   Total Purchase
Name and Address   Purchased Shares    Warrants   Units Purchased       Price
----------------   ----------------   ---------   ---------------   --------------
<S>                <C>                <C>         <C>               <C>
</TABLE>

<PAGE>

                                   APPENDIX I

                   STOCK CERTIFICATE AND WARRANT QUESTIONNAIRE

      Pursuant to Section 4(k) of the Agreement, please provide us with the
following information:

      1.    The exact name that the Purchaser's Purchased Shares and Purchased
Warrant are to be registered in (this is the name that will appear on your stock
certificate(s)). A nominee name may be used if appropriate:

      ____________________________________________________________________

      2.    The relationship between the Purchaser of the Purchased Shares and
the Purchased Warrant and the Registered Holder listed in response to Item 1
above:

      ____________________________________________________________________

      3.    The mailing address of the Registered Holder listed in response to
Item 1 above:

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________

      4.    The Social Security Number or Tax Identification Number of the
Registered Holder listed in response to Item 1 above:

      ____________________________________________________________________

<PAGE>

                                   APPENDIX II

                REGISTRATION STATEMENT/SUITABILITY QUESTIONNAIRE

Pursuant to Section 4(k) of the Agreement, please provide the information below.
All capitalized terms not defined in this Appendix II shall have the meanings
assigned to them in the Agreement.

PART A

In connection with the preparation of the Registration Statement, please provide
us with the following information:

      5.    Pursuant to the "Selling Stockholder" section of the Registration
Statement, please state the Purchaser's name exactly as it should appear in the
Registration Statement:

      ____________________________________________________________________

      6.    Please provide the number of shares of Common Stock that the
Purchaser will own immediately after Closing, including those Shares purchased
by the Purchaser pursuant to the Agreement and those shares purchased by the
Purchaser through other transactions:

      ____________________________________________________________________

      7.    Please explain the nature of the beneficial ownership of the shares
of Common Stock owned by the Purchaser organization, including any shares of
Common Stock not held of record by the Purchaser:

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________

      8.    If the Purchaser is not a natural person, please identify each
natural person who will exercise sole or shared voting and/or dispositive power
with respect to the shares of Common Stock owned by the Purchaser immediately
after the Closing. Please also specify in

<PAGE>

what capacity such person(s) will exercise their voting and/or dispositive power
with respect to such shares.

<TABLE>
<CAPTION>
NATURAL PERSON(S)   RELATIONSHIP TO PURCHASER
-----------------   -------------------------
<S>                 <C>
</TABLE>

      9.    Disclose the details of any rights to acquire shares of Common Stock
that the Purchaser may have:

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________

      10.   Has the Purchaser had any material relationship within the past
three years with the Company or its affiliates?

      Yes [ ] No [ ]

      If yes, please indicate the nature of any such relationships below:

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________

      ____________________________________________________________________
<PAGE>
      11.   Is the Purchaser a broker-dealer registered with the SEC?

            Yes  [ ]      No  [ ]

      12.   Is the Purchaser affiliated with any registered broker-dealer?

            Yes  [ ]      No  [ ]

      If yes, please identify such broker-dealer and explain the relationship
that such registered broker-dealer has with the Purchaser (including details of
any affiliation or other relationship).

<TABLE>
<CAPTION>
REGISTERED BROKER-DEALER                   RELATIONSHIP TO PURCHASER
------------------------                   -------------------------
<S>                                        <C>
</TABLE>

PART B

Pursuant to Section 4 of the Agreement, please provide us with the following
information, and we will use the Purchaser's responses to qualify the Purchaser
for purposes of federal and state securities laws:

      13.   IDENTIFICATION

      Name: ____________________________________________________________________

      Address of principal place of business:

      __________________________________________________________________________

      __________________________________________________________________________

      __________________________________________________________________________

      __________________________________________________________________________

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      State (or Country) of formation or incorporation: ________________________

      Contact Person: __________________________________________________________

      Telephone Number: ________________________________________________________

      Facsimile Number: ________________________________________________________

      Email Address: ___________________________________________________________

      Type of Entity (corporation, partnership, trust, etc.): __________________

      Social Security or Taxpayer or Employer Identification Number: ___________

      14.   STATUS AS AN ACCREDITED INVESTOR

Please confirm that the Purchaser is an "accredited investor" as defined under
the Securities Act of 1933, as amended (the "Act"), by checking all applicable
boxes to indicate the exemption qualifying you as an accredited investor, as
provided in Rule 501(a) under the Securities Act of 1933, as amended.

      [ ] a corporation, organization described in Section 501(c)(3) of the
Internal Revenue Code, a Massachusetts or similar business trust or a
partnership, in each case, not formed for the purpose of this investment, with
total assets in excess of $5,000,000;

      [ ] a private business development company as defined in Section
202(a)(22) of the Investment Advisers Act of 1940;

      [ ] a Small Business Investment Company licensed by the U.S. Small
Business Administration under Section 301(c) or (d) of the Small Business
Investment Act of 1958;

      [ ] an investment company registered under the Investment Company Act of
1940 or a business development company as defined in Section 2(a)(48) of that
Act;

      [ ] a bank as defined in Section 3(a)(2) or a savings and loan association
or other institution defined in Section 3(a)(5)(A) of the Act acting in either
an individual or fiduciary capacity;

      [ ] an insurance company as defined in Section 2(13) of the Securities
Act;

      [ ] an employee benefit plan within the meaning of Title I of the Employee
Retirement Income Security Act of 1974 whose investment decision is made by a
fiduciary which is either a bank, savings and loan association, insurance
company, or registered investment advisor, or whose total assets exceed
$5,000,000, or, if a self-directed plan, a plan whose investment decisions are
made solely by persons who are accredited investors;

      [ ] a director, executive officer or general partner of the issuer of the
securities being offered or sold;

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      [ ] a natural person whose individual net worth, or joint net worth with
your spouse, at the time of purchase exceeds $1,000,000;

      [ ] a natural person who had an individual income in excess of $200,000 in
each of the two most recent years or joint income with your spouse in excess of
$300,000 in each of those years and has a reasonable expectation of reaching the
same income level in the current year;

      [ ] a trust with total assets in excess of $5,000,000, not formed for the
specific purpose of acquiring the securities offered, purchase is directed by a
sophisticated person as described in Rule 506(b)(2)(ii) of the Securities Act;

      [ ] an entity in which all the equity owners are accredited investors; or

      [ ] other - Please describe:

       _________________________________________________________________________

       _________________________________________________________________________

       _________________________________________________________________________

      15.   RESIDENCE INFORMATION

            Please indicate the jurisdiction in which the Purchaser resides, if
the Purchaser is a natural person, or in which the Purchaser is chartered and
the jurisdiction in which it maintains its principal offices:

       _________________________________________________________________________

      16.   INVESTMENT REPRESENTATION

      Is the Purchaser purchasing the securities offered for its and for
      investment purposes only?

           Yes  [ ]       No  [ ]

      If no, please state for whom is the Purchaser investing and/or the reason
      for investing.

       _________________________________________________________________________

       _________________________________________________________________________

       _________________________________________________________________________

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      17.   SIGNATURE

      The above information is true and correct in all material respects and the
      undersigned recognizes that the Company and its counsel are relying on the
      truth and accuracy of such information in reliance on the exemption under
      the Securities Act. The undersigned agrees to notify the Company promptly
      of any changes in the foregoing information which may occur prior to the
      investment.

      Executed at _________________________, _____________________on
      ___________, 2004.

      Name of Entity:__________________________________________________________

      By: __________________________________
      (Signature)

      _____________________________________
      (Name and title of signatory)

IF THE INVESTMENT WILL BE MADE BY MORE THAN ONE ENTITY, WHETHER OR NOT
AFFILIATED, PLEASE COMPLETE A COPY OF THIS QUESTIONNAIRE FOR EACH ENTITY.